相关论文: $\mu - e$ Conversion With Four Generations
Improved upper bounds are presented on the coupling $|U_{e4}|^2$ of an electron to a sterile neutrino $\nu_4$ from analyses of data on nuclear and particle decays, including superallowed nuclear beta decays, the ratios…
The Mu2e experiment will search for the charged-lepton flavor violating (CLFV) neutrino-less conversion of a negative muon into an electron in the field of a nucleus. The conversion process results in a monochromatic electron with an energy…
A detailed discussion is given of the analysis of recent data to obtain improved upper bounds on the couplings $|U_{e4}|^2$ and $|U_{\mu 4}|^2$ for a mainly sterile neutrino mass eigenstate $\nu_4$. Using the excellent agreement among…
We have derived constraints on the tau neutrino mass and fourth generation mixing from an analysis of the partial widths of tau lepton decays, in particular: tau -> e nu nu_tau, tau -> mu nu nu_tau, tau -> pi nu_tau, tau -> K nu_tau. We…
Models involving large extra spatial dimension(s) have interesting predictions on lepton flavor violating processes. We consider some 5D models which are related to neutrino mass generation or address the fermion masses hierarchy problem.…
We analyze the lepton flavor violating process $\mu-e$ conversion in the framework of the minimal R-symmetric supersymmetric standard model. The theoretical predictions are determined by considering the experimental constraint on parameter…
The search for the Lepton Flavor Violating decay $\mu \to e \gamma$ exploits the most intense continuous muon beams, which can currently deliver $\sim 10^8$ muons per second. In the next decade, accelerator upgrades are expected in various…
Using a 3 + 1 neutrino model with one sterile and the three standard active neutrinos with a 4x4 unitary transformation matrix, U, relating flavor to mass neutrino states, the probability of $\nu_\mu$ to $\nu_e$ transition is estimated…
We use the BNL E821 measurement of g - 2, the anomalous magnetic moment of the muon, to normalize, within a supersymmetric GUT framework, constrained MSSM (CMSSM) predictions for processes that violate charged-lepton flavour conservation,…
For a model with a fourth family of quarks, new sources of flavor changing neutral currents are identified by confronting the unitary 4x4 quark mixing matrix with the experimental measured values of the familiar 3x3 quark mixing matrix. By…
We present an illustrative discussion of the physics potential of $\mu^-$- $e^+$ conversion. We point out that this process, although much less frequently studied than the related but much more popular processes of $\mu^-$- $e^-$ conversion…
Predicting the rate for $\mu\to e$ conversion in nuclei for a given set of effective operators mediating the violation of lepton flavor symmetry crucially depends on hadronic and nuclear matrix elements. In particular, the uncertainties…
Within framework of the $\mu$ from $\nu$ Supersymmetric Standard Model ($\mu\nu$SSM), three exotic right-handed neutrino superfields induce new sources for lepton-flavor violation. In this work, we investigate muon conversion to electron in…
We take a fresh look at the limits on the number of neutrino flavors derived from big bang nucleosynthesis. In particular, recent measurements of the \he4 abundance enable one to estimate the primordial \he4 mass fraction at $Y_p = 0.232…
We study the lepton flavor violating $\mu^- \to e^{-}2\gamma $ decay induced by the mediation of heavy leptons such as the excited and fourth generation leptons. We have examined the effects of these leptons in the $\mu^- \to e^{-}2\gamma $…
The flavor-violating decay of a new neutral massive gauge boson $Z^\prime\to\mu e$ is analyzed in the context of extended models, in which this particle emerges. By means of the analysis of the $\mu\to e\gamma$ decay, $\mu-e$ conversion…
New data on the lepton mixing angle $\theta_{13}$ imply that the $e\mu$ element of the matrix $m_\nu m_\nu^\dagger$, where $m_\nu$ is the neutrino Majorana mass matrix, cannot vanish. This implies a lower limit on lepton flavor violating…
The experimental sensitivity to $\mu \to e$ conversion on nuclei is expected to improve by four orders of magnitude in coming years. We consider the impact of $\mu \to e$ flavour-changing tensor and axial-vector four-fermion operators which…
We suggest that $e\to \mu$ conversion in low-energy electron-nucleus scattering is a new and potentially observable indirect signal of supersymmetry and should be searched for in experiment. We estimate the rate for this process in a…
While conventional oscillation experiments measure neutrino mixing parameters with high precision, these measurements are strictly confined to sub-TeV scales. At higher energies, renormalization-group effects can cause these parameters to…